1. Field of the Invention
The present invention relates to a battery-monitoring device.
Priority is claimed on Japanese Patent Application No. 2011-222859, filed on Oct. 7, 2011, the content of which is incorporated herein by reference.
2. Description of Related Art
As is well known, a motor which is used as a source of power, and a high voltage and capacity battery that supplies power to the motor are mounted to vehicles such as an electric automobile and a hybrid automobile. The high-voltage battery is configured such that a plurality of battery cells formed of a lithium-ion-battery, a nickel-hydrogen battery or the like are connected to each other in series.
In the related art, a voltage of each battery cell constituting the above-mentioned high-voltage battery is detected using a voltage detection circuit (for example, a dedicated IC chip), and the presence or absence of battery cells which are in an overcharged state is monitored. However, when the voltage detection circuit is out of order, the voltage of the battery cell cannot be accurately detected (voltage is detected as being low), and thus there is a concern that the presence of overcharged cells may fail to be noticed.
For this reason, a technique has been developed which prevents an overcharged cell from failing to be noticed by using a voltage detection result of the other voltage detection circuit even when one voltage detection circuit is out of order through the duplication of the voltage detection circuit (see Japanese Unexamined Patent Application, First Publication No. 2008-141954).
However, in the above-mentioned related art, since duplication of the voltage detection circuit such as, for example, a dedicated IC chip is required, there is a problem in that an increase in component costs, mounting space, and current consumption is caused.
The invention is contrived in view of such circumstances, and an object thereof is to provide a battery-monitoring device which is capable of preventing overcharged cells due to circuit failure from failing to be noticed while suppressing an increase in component costs, mounting space, and current consumption.